Midea MSA-OASIS-P25-I User Manual page 141

Air Evacuation
Preparations and Precautions
Air and foreign matter in the refrigerant circuit
can cause abnormal rises in pressure, which
can damage the air conditioner, reduce its
efficiency, and cause injury. Use a vacuum pump
and manifold gauge to evacuate the refrigerant
circuit, removing any non-condensable gas and
moisture from the system.
Evacuation should be performed upon initial
installation and when unit is relocated.
BEFORE PERFORMING EVACUATION
Check to make sure that both high-

pressure and low-pressure pipes between
the indoor and outdoor units are
connected properly in accordance with the
Refrigerant Piping Connection section of
this manual.
Check to make sure all wiring is connected

properly.
MC
Evacuation Instructions
Before using the manifold gauge and vacuum
pump, read their operation manuals to familiarize
yourself with how to use them properly.
Low pressure valve
1.
2.
3.
4.
5.
MC
Manifold Gauge
Compound gauge Pressure gauge
-76cmHg
Pressure hose /
Charge hose
Low pressure valve
Fig. 6.1
Connect the charge hose of the manifold
gauge to service port on the outdoor unit's
low pressure valve.
Connect another charge hose from the
manifold gauge to the vacuum pump.
Open the Low Pressure side of the manifold
gauge. Keep the High Pressure side closed.
Turn on the vacuum pump to evacuate the
system.
Run the vacuum for at least 15 minutes, or
until the Compound Meter reads -76cmHG
5
(-10 Pa).
7
High pressure
valve
Charge hose
Vacuum
pump
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